docs: def create(title='', sites=None, mobile_sites=None, align='left', addition_class=''):
          """Create a share component.
  
          :param title: the prompt displayed on the left of the share component.
          :param sites: a string that consist of sites, separate by comma.
                        supported site name: weibo, wechat, douban, facebook, twitter,
                        google, linkedin, qq, qzone.
                        for example: `'weibo, wechat, qq'`.
          :param mobile_sites: the sites displayed on mobile.
          :param align: the align of the share component, default to `'left'`.
          :param addition_class: the style class added to the share component.
          """
          if current_app.config['SHARE_HIDE_ON_MOBILE']:
              platform = request.user_agent.platform
              if platform is not None:
                  mobile_pattern = re.compile('android|fennec|iemobile|iphone|opera (?:mini|mobi)')
                  m = re.match(mobile_pattern, platform)
                  if m is not None:
                      return ''
  
          if sites is None:
              sites = current_app.config['SHARE_SITES']
          if mobile_sites is None:
              mobile_sites = current_app.config['SHARE_MOBILE_SITES']
          return Markup('''<div class="social-share %s" data-sites="%s" data-mobile-sites="%s"
          align="%s">%s</div>''' % (addition_class, sites, mobile_sites, align, title))